A turbine part of a gas turbine used for a generator or the like comprises a moving blade member which rotates together with a rotor and a stationary blade member fixed in_a compartment, the moving blade member consisting of a platform to be connected with the rotor and a moving blade, the stationary blade member consisting of a stationary blade, and an inner shroud and an outer shroud fixed to each end of the stationary blade.
A blade surface of the stationary blade and the inner and the outer shrouds form a passage wall for high temperature gas flowing through the turbine part, and also a blade surface of the moving blade and the platform form a passage wall for high temperature gas. Furthermore, in the compartment, a division ring forming a passage wall for high temperature gas together with the blade surface of the moving blade and the platform is fixed while interposing a certain space between a tip end of the moving blade. The provision ring is formed of a plurality of division ring sections that are connected in the direction of arrangement of moving blade, and forms a wall surface of a circular ring cross section as a whole.
On the other hand, also the moving blade and the stationary blade are divided into a plurality of sections in the peripheral direction of the rotor for the reason of performance such as for absorbing heat deformation, for the reason of manufacture, for the reason of maintainability and the like, and a plural number of shroud sections and platform sections are connected in the direction of arrangement of blade in the same manner as the division ring to formal wall surface having a roughly circular cross section as a whole.
When the shroud sections, platform sections and division ring sections are, respectively connected in the peripheral direction of the rotor, it is necessary to previously keep a gap between the connected shroud sections, between the connected platform sections, between the connected division ring sections. This is because the shroud sections, platform sections and division ring sections will expand by heat in also the peripheral direction due to exposure to high temperature gas, and it is desired to design so that these gaps will completely disappear in the state that these sections expand by heat.
In other words, in the condition that high temperature gas flows through the passage formed by the blade surface, shroud, platform or division ring, the high temperature gas will leak outside from the gap formed between the connected shroud sections and the like, which may cause decrease in turbine efficiency, or occurrence of unexpected failure due to deposition of soil by the high temperature gas which is burned gas.
However, in practice, it is impossible to make the gap completely disappear under high temperature, in consideration of allowance in production and the like. For this reason, in a conventional approach, for example, as is the case of a platform 43 shown in FIG. 10, a sealing member 45 is provided across the platforms 43 to be connected with each other, thereby preventing high temperature gas V1 from leaking outside a gap 44. Such a sealing member 45 is also provided between the shroud sections and between the division ring sections.
In this way, although the high temperature gas V1 is prevented from leaking outside by means of the sealing member 45, the gap 44 between the sections to be connected still exists, so that there is a possibility that the high temperature gas V1 passes through the gap 44 from an opening 44a of the gap 44 on the upstream side of the flow direction of the high temperature gas V1 and burns the surface of the gap 44, i.e., a side end surface 43a of the division wall section of the platform 43 and the like. Furthermore, there is a possibility that regardless of the position in the flow direction of the high temperature gas V1, the high temperature gas V1 is embraced in the gap 44 to burn the side end surface 43a of the division wall section.